From: Sebastian Sanchez <sebastian.sanchez@xxxxxxxxx>
The atomic SDMA_REQ_SEND_DONE bit is set by the
process-level code, and then the same process-level
code uses the bit to test that all packets have been
submitted incurring a costly atomic read.
Use a bool type with a READ_ONCE/WRITE_ONCE
pairing for this bit, and use the same condition that
is used to set the bit to test that all packets have
been submitted.
Reviewed-by: Mike Marciniszyn <mike.marciniszyn@xxxxxxxxx>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@xxxxxxxxx>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@xxxxxxxxx>
---
drivers/infiniband/hw/hfi1/user_sdma.c | 14 +++++++-------
1 files changed, 7 insertions(+), 7 deletions(-)
diff --git a/drivers/infiniband/hw/hfi1/user_sdma.c b/drivers/infiniband/hw/hfi1/user_sdma.c
index 92517ce..6fb70f0 100644
--- a/drivers/infiniband/hw/hfi1/user_sdma.c
+++ b/drivers/infiniband/hw/hfi1/user_sdma.c
@@ -154,10 +154,8 @@
#define TXREQ_FLAGS_REQ_DISABLE_SH BIT(1) /* Disable header suppression */
/* SDMA request flag bits */
-#define SDMA_REQ_FOR_THREAD 1
-#define SDMA_REQ_SEND_DONE 2
-#define SDMA_REQ_HAS_ERROR 3
-#define SDMA_REQ_DONE_ERROR 4
+#define SDMA_REQ_HAS_ERROR 1
+#define SDMA_REQ_DONE_ERROR 2
#define SDMA_PKT_Q_INACTIVE BIT(0)
#define SDMA_PKT_Q_ACTIVE BIT(1)
@@ -258,6 +256,7 @@ struct user_sdma_request {
u16 tididx;
/* progress index moving along the iovs array */
u8 iov_idx;
+ u8 done;
struct user_sdma_iovec iovs[MAX_VECTORS_PER_REQ];
} ____cacheline_aligned_in_smp;
@@ -628,6 +627,7 @@ int hfi1_user_sdma_process_request(struct hfi1_filedata *fd,
req->seqsubmitted = 0;
req->flags = 0;
req->tids = NULL;
+ req->done = 0;
INIT_LIST_HEAD(&req->txps);
memcpy(&req->info, &info, sizeof(info));
@@ -809,7 +809,7 @@ int hfi1_user_sdma_process_request(struct hfi1_filedata *fd,
* request have been submitted to the SDMA engine. However, it
* will not wait for send completions.
*/
- while (!test_bit(SDMA_REQ_SEND_DONE, &req->flags)) {
+ while (req->seqsubmitted != req->info.npkts) {
ret = user_sdma_send_pkts(req, pcount);
if (ret < 0) {
if (ret != -EBUSY) {
@@ -1118,7 +1118,7 @@ static int user_sdma_send_pkts(struct user_sdma_request *req, unsigned maxpkts)
ret = sdma_send_txlist(req->sde, &pq->busy, &req->txps, &count);
req->seqsubmitted += count;
if (req->seqsubmitted == req->info.npkts) {
- set_bit(SDMA_REQ_SEND_DONE, &req->flags);
+ WRITE_ONCE(req->done, 1);
/*
* The txreq has already been submitted to the HW queue
* so we can free the AHG entry now. Corruption will not
@@ -1585,7 +1585,7 @@ static void user_sdma_txreq_cb(struct sdma_txreq *txreq, int status)
if (status != SDMA_TXREQ_S_OK)
req->status = status;
if (req->seqcomp == (ACCESS_ONCE(req->seqsubmitted) - 1) &&
- (test_bit(SDMA_REQ_SEND_DONE, &req->flags) ||
+ (READ_ONCE(req->done) ||
test_bit(SDMA_REQ_DONE_ERROR, &req->flags))) {
user_sdma_free_request(req, false);
pq_update(pq);
--
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